U.S. patent number 8,105,311 [Application Number 10/725,374] was granted by the patent office on 2012-01-31 for catheter with bendable section.
This patent grant is currently assigned to Abbott Laboratories Vascular Enterprises Limited. Invention is credited to Judith Hartwig, Stevan Nielsen, Ralph Schneider.
United States Patent |
8,105,311 |
Schneider , et al. |
January 31, 2012 |
Catheter with bendable section
Abstract
A catheter is configured to prevent kinking of a catheter during
handling or mounting of a pressure device. The catheter has a
proximal end of its catheter shaft that is provided with a bending
section having a flexibility greater than that of the section of
the catheter shaft joining the proximal end.
Inventors: |
Schneider; Ralph (Rangendingen,
DE), Hartwig; Judith (Dotternhausen, DE),
Nielsen; Stevan (Rottenburg, DE) |
Assignee: |
Abbott Laboratories Vascular
Enterprises Limited (Dublin, IE)
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Family
ID: |
32319582 |
Appl.
No.: |
10/725,374 |
Filed: |
December 3, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040116850 A1 |
Jun 17, 2004 |
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Foreign Application Priority Data
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Dec 11, 2002 [EP] |
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02027767 |
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Current U.S.
Class: |
604/523;
604/96.01 |
Current CPC
Class: |
A61M
25/0606 (20130101); A61M 25/0054 (20130101) |
Current International
Class: |
A61M
25/00 (20060101); A61M 29/00 (20060101) |
Field of
Search: |
;604/19,1,48,523,96.01,525,264,533,534,535,536,96,99,164.03,280,281,282
;606/108,191,99 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2085978 |
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Oct 1992 |
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CA |
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2085978 |
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Oct 1992 |
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CA |
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3907549 |
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Sep 1990 |
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DE |
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3907549 |
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Sep 1990 |
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DE |
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0792655 |
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Sep 1997 |
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EP |
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0792655 |
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Sep 1997 |
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EP |
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0937480 |
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Aug 1999 |
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EP |
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0937480 |
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Aug 1999 |
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EP |
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1290933 |
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Apr 1962 |
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FR |
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WO 92/18193 |
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Oct 1992 |
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WO |
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WO 9218193 |
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Oct 1992 |
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WO |
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WO 96/16690 |
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Jun 1996 |
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WO |
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WO 9616690 |
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Jun 1996 |
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WO |
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Primary Examiner: Lucchesi; Nicholas
Assistant Examiner: Campbell; Victoria P
Attorney, Agent or Firm: Workman Nydegger
Claims
What is claimed is:
1. A catheter comprising: a catheter shaft having a distal end and
a proximal end, the proximal end including a bending section
extending distally from the proximal end toward but not to the
distal end of the catheter shaft, the bending section distal end
terminating proximal the distal end of the catheter shaft and
comprising one or more spiral cuts in the catheter shaft, the
bending section having a flexibility greater than the flexibility
of the portion of the catheter shaft adjacent the bending section;
a balloon secured to the distal end of the catheter shaft, a
proximal end of the balloon being spaced apart distally from the
distal end of the bending section, the flexibility of the catheter
shaft adjacent the balloon being lesser than the flexibility of the
catheter shaft at the bending section; a fitting secured to the
proximal end of the catheter shaft, the fitting including a
passageway in fluid communication with the catheter shaft and
receiving at least a portion of the bending section of the catheter
shaft, including at least a portion of the one or more spiral cuts;
and a fluid impermeable covering extending from the bending section
toward but not to the distal end of the catheter shaft to seal the
bending section.
2. The catheter of claim 1, wherein the fitting is a luer
fitting.
3. The catheter of claim 1, wherein the spiral cut is formed with a
selectable number of spiral sections.
4. The catheter of claim 1, wherein the fluid impermeable covering
is shaped as a sleeve or a tube.
5. The catheter of claim 1, wherein the fluid impermeable covering
is adhesively bonded to the bending section.
6. The catheter of claim 1, wherein the fitting comprises a
transition member connected to the proximal end, and wherein the
transition member is structured to prevent unintended kinking of at
least a portion of the bending section.
7. The catheter of claim 1, wherein the catheter shaft has a lumen
and the passageway of the fitting is in fluid communication with
the lumen.
8. The catheter of claim 1, wherein the portion of the catheter
shaft that is adjacent to the balloon has lesser flexibility than
the portion of the catheter shaft at the bending section that is
proximal to the balloon.
9. The catheter of claim 1, wherein the bending section has a
flexibility greater than the flexibility of the portion of the
catheter shaft adjacent and distal to the bending section.
10. The catheter of claim 1, wherein the fluid impermeable covering
extends distally toward but not to the balloon.
11. A catheter comprising: a fitting including a passageway; a
catheter shaft including a distal end and a proximal end, the
proximal end being disposed within the fitting, which is in fluid
communication with the catheter shaft, the proximal end of the
catheter shaft including a bending section extending distally from
the proximal end toward but not to the distal end of the catheter
shaft, at least a portion of the bending section being disposed
within the fitting and a distal end of the bending section
terminating proximal the distal end of the catheter shaft and
comprising one or more cuts in the catheter shaft, wherein at least
a portion of the one or more cuts is disposed within the fitting,
the bending section having a flexibility greater than the
flexibility of the remainder of the catheter shaft; a fluid
impermeable covering extending from the bending section toward but
not to the distal end of the catheter shaft to seal the one or more
cuts of the bending section, a proximal portion of the fluid
impermeable covering located within the passageway of the fitting;
and a balloon secured to the distal end of the catheter shaft so as
to be spaced apart distally from the bending section, the
flexibility of the catheter shaft adjacent the balloon being lesser
than the flexibility of the catheter shaft at the bending
section.
12. The catheter of claim 11, wherein the one or more cuts are
spiral cuts.
13. The catheter of claim 12, wherein the cuts increase in pitch
towards the distal end.
14. The catheter of claim 11, wherein the fitting comprises a
transition member coupled to the catheter shaft the transition
member extending over the proximal end of the catheter shaft and a
proximal portion of the bending section.
15. The catheter of claim 11, wherein the fitting is a luer
fitting.
16. A catheter comprising: a catheter shaft having a distal end, a
proximal end, and a first outer cross-sectional diameter, the
proximal end including a bending section, the bending section
extending distally from the proximal-most proximal end of the
catheter shaft toward but not to the distal end, the bending
section distal end terminating proximal the distal end of the
catheter shaft and comprising one or more cuts in the catheter
shaft, the bending section having a flexibility greater than the
flexibility of the portion of the catheter shaft adjacent the
bending section; a balloon secured to the distal end of the
catheter shaft, a proximal end of the balloon being spaced apart
distally from the distal end of the bending section, the
flexibility of the catheter shaft adjacent the balloon being lesser
than the flexibility of the catheter shaft at the bending section;
a fitting secured to the proximal end of the catheter shaft and
having a second inner cross-sectional diameter greater than the
first outer cross-sectional diameter, the fitting receiving at
least a portion of the bending section of the catheter shaft,
including at least a portion of the one or more spiral cuts; and a
fluid impermeable covering extending from the bending section
toward but not to the distal end of the catheter shaft to seal the
bending section.
17. The catheter of claim 16, wherein the one or more cuts are
spiral cuts.
18. The catheter of claim 16, wherein the fitting comprises a
transition member coupled to the catheter shaft.
19. The catheter of claim 18, wherein the transition member extends
over the proximal end of the catheter shaft, a proximal portion of
the bending section, and a proximal portion of the fluid
impermeable covering.
20. The catheter of claim 16, further comprising an inflation
device coupled to the fitting for expanding the balloon.
21. The catheter of claim 16, wherein the fitting is a luer
fitting.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a catheter that is not prone to
kinking.
2. Background Information
A generic catheter is disclosed in U.S. Pat. No. 5,569,200, which
basically comprises a catheter shaft that is normally designated as
a "hypotube". A fitting, preferably in the form of a luer fitting,
is provided at the proximal end of said catheter shaft and serves
to connect a pressure device via which pressurized fluid is
introduced through channels provided in the fitting so as to expand
the balloon at the distal end of the catheter shaft.
In view of the above, there exists a need for an improved catheter.
This invention addresses this need as well as other needs, which
will become apparent to those skilled in the art from this
disclosure.
SUMMARY OF THE INVENTION
Investigations conducted within the scope of the present invention
have shown that the transition point between hypotube and fitting
is very sensitive to kinking. The user may kink the catheter shaft
when removing the shaft from the packaging and the protective cover
or when connecting the pressure device. Investigations conducted
within the scope of the present invention have shown that at least
one of the reasons for said undesired kinking is the fact that the
catheter shaft has a very small diameter so that, when removing the
catheter shaft from the packaging or when connecting the pressure
device, the user does not feel the catheter shaft in a sufficiently
distinct way and may thus kink it without intention. Kinking is
particularly critical for the reason that it may lead to an
occlusion of the inflation lumen, which makes the catheter
inoperative.
It is therefore the object of the present invention to provide a
catheter which has improved handling characteristics and is
particularly not prone to kinking.
This object is achieved through a catheter comprising a catheter
shaft including a proximal end and a distal end having preferably
secured thereto a balloon, and a fitting, preferably a luer
fitting, arranged at the proximal end of the catheter shaft. The
proximal end of the catheter shaft can include a bending
section.
Although the generic prior art according to U.S. Pat. No. 5,569,200
refers to the sensitivity to kinking and to the provision of slits
in the catheter shaft as a possible solution for this problem, the
slits are provided at the distal end, at which point no forces are
acting in a direction transverse to the longitudinal axis of the
catheter, since there are only forces applied in the direction of
the longitudinal axis of the catheter. In this respect the slits
cannot solve the above-explained problem because in the generic
catheter there is still the risk of kinking or even breaking upon
application of external forces, as has been described above.
By contrast, the deliberate provision of a bending section at the
proximal end of the catheter shaft in accordance with the invention
solves the technical problem underlying the invention in a
surprisingly simple and unforeseeable way because the deliberate
provision of a bending section exactly in the critical region of
the catheter shaft that is particularly sensitive to kinking in the
generic catheter creates increased flexibility which, although it
permits an intended bending, reliably prevents undesired kinking or
even breaking because a plastic deformation of the catheter shaft
is prevented.
U.S. Pat. No. 6,387,075 discloses a further catheter which has a
spiral cut into the hypotube distally of the woven catheter shaft.
Said spiral, however, is just meant to improve the flexibility of
the catheter shaft in the distally situated region of the catheter.
Therefore, according to the above-mentioned U.S. Pat. No.
5,569,200, the spiral cannot prevent the risk of kinking of the
catheter behind the fitting.
Furthermore, it is described in U.S. Pat. No. 6,387,075 that for
preventing kinking of the catheter behind the fitting the proximal
catheter shaft is reinforced with a polymer over a length of about
6 to 12 inches or stabilized by way of reinforcement. Said
reinforcement, however, just shifts the point of kinking in distal
direction towards the end of the reinforcement. Moreover, the
polymer reinforcement reduces the available and usable length of
the catheter, thus resulting in an undesired extension of the
catheter shaft.
Finally, in a further embodiment for reinforcing the proximal
catheter shaft, U.S. Pat. No. 6,387,075 describes a catheter whose
proximal shaft consists, instead of a hypotube, of a woven fabric
placed between an inner and an outer polymer tube. This embodiment
avoids the problem of kinking of the catheter by installation of a
catheter section that does not consist of the hypotube, but is made
up of novel additional shaft components. This, however, entails
considerable drawbacks due to reduced pushability and a troublesome
and expensive production of the catheter.
When the bending section of the present invention is designed as a
cut-in spiral or as a plurality of offset cuts or incisions with
suitable seals, this will entail the advantage that the bending
section can be produced in a very simple manner without the use of
additional materials, which reliably prevents damage to the
catheter shaft. This yields a deliberate weakening of the material
that leads to the desired increase in flexibility and thus kink
protection.
According to another aspect of the present invention, the bending
section is designed as a soft-annealed material section of the
catheter shaft which in a particularly advantageous embodiment can
be surrounded by a spiral spring for enhancing the stability
thereof.
As a rule, it is also possible to form the bending section as a
transitional section of the fitting from a flexible plastic
material, which in a particularly preferred embodiment has an
undercut which can be engaged by a complementary holding member of
the proximal end of the catheter shaft for securing the
position.
In a further alternative embodiment, the bending section is formed
by a plurality of balls which are mounted on the proximal end of
the catheter shaft. The balls can be provided on the catheter shaft
(hypotube) either mechanically, or they may be formed thereon by an
adhesive, by welding or as one piece. Furthermore, it is possible
to provide a heat shrinkable tube over the balls for fixing the
position.
One object according to the invention is achieved in this
embodiment by mechanically restricting the maximum bending degree
or converting the bending operation into a sufficiently large
radius, which also prevents a plastic deformation of the plastic
dimension or at least reduces it to a tolerable degree.
The arising forces that are greater than a possible maximum bending
angle can be converted into longitudinal stress on the catheter
shaft which is able to withstand said stress due to its material
characteristics much better than bending forces.
Finally, it is fundamentally possible to form a spring on the
proximal end of the catheter shaft, e.g. in the form of a flexible
spiral spring which is connected to the fitting in the kink-prone
region, so that the plastic deformation of the catheter shaft
itself can also be prevented.
These and other objects, features, aspects and advantages of the
present invention will become apparent to those skilled in the art
from the following detailed description, which, taken in
conjunction with the annexed drawings, discloses a preferred
embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the attached drawings which form a part of this
original disclosure:
FIG. 1 is a schematically strongly simplified illustration of a
catheter according to the present invention;
FIGS. 2 and 3 are illustrations corresponding to FIG. 1, which show
possible designs of the bending section in the form of offset
cuts;
FIG. 4 is an illustration corresponding to FIG. 1, which shows a
second embodiment of the catheter according to the present
invention;
FIG. 5 is an enlarged illustration of detail A in FIG. 4;
FIG. 6 is an illustration corresponding to FIG. 1, which shows a
third, fundamentally possible embodiment of the catheter according
to the invention; and
FIGS. 7-9 are illustrations showing parts of the catheter
illustrated in FIG. 6, for explaining the function of the
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Selected embodiments of the present invention will now be explained
with reference to the drawings. It will be apparent to those
skilled in the art from this disclosure that the following
description of the embodiments of the present invention is provided
for illustration only, and not for the purpose of limiting the
invention as defined by the appended claims and their
equivalents.
Referring initially to FIG. 1, a catheter 1 is illustrated in
accordance with a first embodiment of the present invention. The
catheter 1 of the present invention basically comprises a catheter
shaft 2 provided with a proximal end 3 and a distal end 4, which
are shown in FIG. 1 in a strongly shortened condition. A balloon
24, which is only illustrated schematically, is secured to the
distal end 4. Furthermore, the catheter 1 comprises a fitting 5
which is normally designed as a luer fitting. The fitting 5 is
secured to the proximal end 3 of the catheter shaft 2 and may
comprise a housing 25 of a standard construction with a passageway
26 in flow communication with the catheter shaft 2. The fitting 5
is connected to a pressure device (inflation device) for expanding
the balloon 24.
The proximal end 3 of the catheter shaft 2 of the catheter 1
according to the invention is provided with a bending section 6
having a flexibility greater than that of the section 3' of the
catheter shaft 2 joining the proximal end 3. Said bending section 6
prevents unintended kinking in the way explained at the outset.
In the embodiment which is shown in FIG. 1 and particularly
preferred, the bending section 6 is designed as a spiral 7 that is
cut into the catheter shaft 2 and formed with a selectable number
of spiral sections.
For preventing liquid from exiting, the spiral 7 is provided with a
seal 8 which may be designed as a sleeve or tube that is secured,
preferably by an adhesive, to the proximal section 3.
As illustrated in FIG. 1, the proximal end 3 is connected with its
bending section 6 and the seal 8 arranged thereabove to a
transition member 16 of the fitting 5, so that the region of the
catheter shaft 2 that is prone to kinking is protected from
unintended kinking.
FIGS. 2 and 3 show alternative embodiments of the bending section
6. In the embodiment shown in FIG. 2, the bending section 6 is
formed at the proximal end 3 by a plurality of offset slits, which
in the exemplary case are represented by two slits 9 and 11. The
slits 9 and 11 extend up to webs 10 and 12, respectively, the
arrangement of which yields the offset. The slits can be adapted in
their dimensions (length, width, angular position) to different
conditions of use.
In FIG. 3, the bending section 6 is also formed at the proximal end
3 by a plurality of offset slits 13, 14 and 15, which in this
embodiment do not extend in circumferential direction as in FIG. 2,
but extend essentially in the longitudinal direction of the
proximal end 3. The slits 13 and 15 have two slit sections, of
which one extends into the edge portion of the proximal end 3 while
the slit 14 comprises three slit sections arranged at an angle
relative to one another between slits 13 and 15.
Second Embodiment
Referring now to FIGS. 4 and 5, a catheter 1 in accordance with a
second embodiment will now be explained. In view of the similarity
between the first and second embodiments, the parts of the second
embodiment that are identical to the parts of the first embodiment
will be given the same reference numerals as the parts of the first
embodiment. Moreover, the descriptions of the parts of the second
embodiment that are identical to the parts of the first embodiment
may be omitted for the sake of brevity. Reference can here be made
to the above explanations.
In the embodiment according to FIG. 4, the transition member 16 is
formed as a flexible plastic section of the fitting 5 that is
connected to the proximal end 3 of the catheter shaft 2. The detail
according to FIG. 5 shows an undercut 17 which can be engaged by a
holding member 18 of the proximal end 3 of the catheter shaft 2 for
fixing the catheter shaft 2.
Third Embodiment
Referring now to FIG. 6, a catheter 1 in accordance with a third
embodiment will now be explained. In view of the similarity between
the third and prior embodiments, the parts of the third embodiment
that are identical to the parts of the prior embodiments will be
given the same reference numerals as the parts of the prior
embodiments. Moreover, the descriptions of the parts of the second
embodiment that are identical to the parts of the first embodiment
may be omitted for the sake of brevity. Reference can here be made
to the above explanations.
In this embodiment, the bending section 6 comprises a plurality of
balls 19 to 23 mounted on the proximal end 3. Said balls can be
fixed to the catheter shaft 2 by way of different fastening
possibilities as have been explained at the outset. In the
embodiment shown in FIG. 6, a heat shrinkable tube 27 is provided
for this purpose, said tube being connected at one end to the
catheter shaft 2 and fixed at the other end to the fitting 5.
FIGS. 7 and 8 illustrate the function of the embodiment with
reference to two balls 19 and 20. It becomes apparent that the
balls can be dimensioned in their distance d and in their radius r
(see FIG. 9) in such a way that a maximally acceptable bending
angle .alpha. (see FIG. 9) is made possible. This angle .alpha.
does not entail any plastic deformation and thus kinking or even
breaking of the catheter shaft.
Catheters without a balloon shall also be regarded as catheters
according to the invention.
The terms of degree such as "substantially", "about" and
"approximately" as used herein mean a reasonable amount of
deviation of the modified term such that the end result is not
significantly changed. These terms should be construed as including
a deviation of at least .+-.5% of the modified term if this
deviation would not negate the meaning of the word it modifies.
This application claims priority to European Patent Application No.
02027767.9. The entire disclosure of European Patent Application
No. 02027767.9 is hereby incorporated herein by reference.
While only selected embodiments have been chosen to illustrate the
present invention, it will be apparent to those skilled in the art
from this disclosure that various changes and modifications can be
made herein without departing from the scope of the invention as
defined in the appended claims. Furthermore, the foregoing
descriptions of the embodiments according to the present invention
are provided for illustration only, and not for the purpose of
limiting the invention as defined by the appended claims and their
equivalents.
* * * * *